1. Field of Invention
The technical scope of the present invention is that of devices to control projectile fins, that is devices which, by the action of a motor, enable deployed fins to be pivoted.
2. Description of Related Art
Fins act as stabilizers for a projectile but may also play a role in piloting, similar to the elevons or ailerons of an aircraft, controlled in rotation by a motor piloted by an electronic system. The piloting of the projectile enables its trajectory to be corrected in flight to rectify any launching errors or to orient it towards a target after said target's detection.
Such fins suffer from the principal drawback of needing to be of a large size if they are to be effective (the length of the fin is usually around one caliber), which makes it impossible for the projectile to be fired from a cannon of the same caliber. Thus, for many years, different mechanisms have been developed to deploy fins and elevons. The projectile fitted with such a mechanism may be a missile, a rocket, or sub-projectile. Thus, French patents FR-2864613 and FR-2846079 describe devices to deploy projectile fins and lock them in their deployed position.
Once the fins have been deployed a further mechanism must be provided to enable them to be oriented.
French Patent FR-2846080 describes a device to deploy and pilot projectile fins. The device disclosed in that document enables the simultaneous orientation of pairs of fins integral with a common control shaft. The main advantage of this device lies in its use of only two motors to orient the four fins.
Despite being particularly effective and judicious in design, that device has one major drawback, Indeed, the positioning of the drive motors for the fins and the numerous parts implemented make it particularly voluminous and sensitive to accelerations, namely when the projectile is being fired.